Consider using latest during resolve when tag is not provided

[kranurag7]

What is the version of your ORAS CLI

main

What would you like to be added?

This is a feature request which is an extension to this pull request. This issue requests consideration of falling back to using latest when the tag is not provided by the user.

Why is this needed for ORAS?

Most of the project use latest tag for their dev/staging images. It will be helpful and a good default (IMHO) when it comes to getting the digest of the latest image quickly without explicitly mentioning latest tag every time.

Are you willing to submit PRs to contribute to this feature?

• Yes, I am willing to implement it.

[qweeah]

Tagging a manifest as latest is not a good practice although it is a convention in docker. Many tools like containerd/ctr has dropped the default value of latest. More tagging strategies can be found at Docker Tagging: Best practices for tagging and versioning docker images – Steve Lasker.
Additionally, oras support pushing without a tag while it is not supported by docker.

[kranurag7]

Thanks for the feedback and reference @qweeah
I think we are good to close this.